Deinkability in printed products is key for recyclability, guiding sustainable choices for engineers and product teams.
Deinkability Explained: Why It Matters for Recyclable Printed Products
Recyclability is influenced by more than the material a product is made from. For printed paper products, labels, packaging, and other graphics, the printing process can also affect what happens to the material at the end of its useful life.
One consideration is deinkability, or the ability to remove printing inks or toners from recovered paper during the recycling process. Effective deinking helps recover paper fibers while supporting the quality of the recycled material being produced.
For engineers and product teams evaluating more sustainable printed products, understanding deinkability can help make recyclability part of the conversation when selecting materials and print processes.
What Is Deinkability?
Deinking is the process of separating and removing ink or toner from printed paper so that paper fibers can be recovered for reuse.
This matters because printing introduces another material into a paper-based construction. When ink or toner can be effectively separated during recycling, recovered fibers have greater potential to be reused. Poor deinking results can affect the quality and appearance of the recovered material.
The recyclability question therefore goes beyond determining whether the original substrate is paper. The finished printed construction should also be considered, including how printing and other components may affect its end-of-life options.
Deinkability provides a measurable way to approach part of that evaluation.
How Is Deinkability Scored?
A common way of evaluating the deinkability of printed paper products is through the Deinkability Score. The assessment evaluates five areas: luminosity, color, cleanliness, ink elimination, and filtrate darkening. Because cleanliness considers two different dirt-particle sizes, the calculation ultimately includes six individual scores.
The Deinkability Score can range from -100 to +100, with higher positive scores indicating better deinkability. Scores from 71 to 100 are considered Good, 51 to 70 are Fair, and 0 to 50 are Tolerable. However, the total score does not tell the entire story. If an individual parameter receives a negative score by failing to meet its required threshold, the printed product is considered not suitable for deinking.
Each factor is weighted differently toward the 100 available positive points:
Luminosity: 35 Points
As the largest individual portion of the score, luminosity evaluates the optical quality of the deinked pulp. Greater luminosity indicates a brighter result after the deinking process. This helps assess how much the remaining print affects the brightness of the recovered paper fibers.
Color: 20 Points
Color evaluates the appearance of the deinked pulp and the amount of unwanted coloration that remains. It accounts for up to 20 points of the overall score. Even when pulp achieves sufficient brightness, residual color can still affect the visual quality of the recovered material.
Cleanliness: 25 Points
Cleanliness evaluates remaining dirt or ink particles in the deinked pulp. The 25 available points are divided between particles larger than 50 μm, worth 15 points, and particles larger than 250 μm, worth 10 points. By considering different particle sizes, this portion of the assessment accounts for visible contamination that may remain after ink separation.
Ink Elimination: 10 Points
Ink elimination evaluates how effectively ink is removed during the deinking process. It contributes up to 10 points toward the overall score. This provides an indication of how successfully the printing material has been separated from the paper fibers during processing.
Filtrate Darkening: 10 Points
Filtrate darkening considers ink particles that remain dispersed during the deinking process and can darken the filtrate. This parameter accounts for the final 10 available points. It helps account for fine ink particles that may remain suspended rather than being effectively removed during deinking.
Together, luminosity, color, and cleanliness account for 80 of the 100 available positive points, placing significant weight on the quality of the resulting deinked pulp. Ink elimination and filtrate darkening make up the remaining 20 points. Each parameter also has its own threshold and target values, so a strong total score cannot necessarily compensate for poor performance in an individual category.
Dry Toner and Deinkability
When recyclability is an important consideration for a printed paper product, the ink or toner system becomes another part of the print specification worth evaluating. For electrophotographic digital printing, that means considering the deinking performance of dry toner.
Dry toner can be a strong candidate when deinkability is a priority, with certain dry-toner systems capable of achieving strong deinking performance. The specific result can depend on the toner, substrate, and overall printed construction, making measured deinkability more useful than assuming performance based on the printing method alone.
This gives product teams another factor to consider when evaluating a print process. Deinkability can be weighed alongside image quality, durability, production requirements, and the other functional needs of the application.
The Deinkability Score provides a way to measure that performance and better understand how a printed paper product may behave during the deinking process. From there, the results can become one part of a broader assessment of the finished product's recyclability.
Consider the Complete Printed Construction
Deinkability addresses an important aspect of paper recycling, but the ink or toner is only one part of the finished product.
Depending on the application, a printed construction may incorporate coatings, laminates, adhesives, or additional materials. Those components may be necessary to achieve durability, protection, functionality, or other performance requirements.
For product teams balancing performance and recyclability, several questions can help guide the conversation:
- Is the selected substrate appropriate for the intended recycling stream?
- How does the ink or toner perform during deinking?
- Are additional coatings, laminates, or layers required for the application?
- Are there opportunities to simplify the material construction?
- Is recyclability being considered at the individual material level or for the finished product?
- Can print and converting decisions be evaluated earlier in product development?
There may not be a single material or manufacturing process that determines the answer. Bringing these considerations together earlier gives engineers and product teams more opportunity to evaluate the trade-offs before the final construction has been established.
Let’s Make Something Great
Deinkability gives product teams a measurable way to consider how printing may affect paper recyclability. Evaluating the substrate, ink or toner, and overall construction early in development can help teams make more informed decisions while balancing recyclability with the performance requirements of the application.
Tapecon combines expertise in printing, materials, converting, and engineering solutions to help product teams evaluate those decisions and develop manufacturable solutions. If recyclability or deinkability is a priority for your next printed product, contact Tapecon to discuss your application.
